E-mail this article

Sending your article

Your article has been sent.

Fall may be New England’s most gentle season, with the weather just right, foliage bursting like fireworks, and only a faint foreboding of the coming winter gloom.

But in many parts of the region this time of year, particularly this year, the sky is falling - or at least it feels that way. Hard-shelled orbs are cracking windshields, thwacking gardeners, and tripping up joggers on their daily slog.

They are also making squirrels and other rodents pleasantly plump, leading to a potential bulge in their population.

Given this year’s bountiful rains and the mysterious cycles of nature, oak trees are producing one of the region’s largest crops of acorns in memory, forcing people to run for cover or gingerly avoid what can feel like a carpet of marbles on sidewalks and backyards.

On a recent afternoon along the Muddy River, the spike-tipped, leathery shells plunged like cluster bombs with every gust of wind from the surrounding oaks, leaving thousands of them littering the paved paths that connect Boston and Brookline.

“I’ve nearly broken my neck several times,’’ said Neil McIsaac, a Brookline contractor who was installing a fence along the river. “There are tons of them.’’

Like other outdoor workers this autumn, McIsaac and his colleagues are trying to get used to the random thuds. “Every time I hear one, I think it’s a kid throwing a rock at me,’’ said Greg Roberson, who was digging a hole for the fence. “They’re falling everywhere.’’

Scientists say oak trees produce bumper crops of acorns every two to seven years, but that the record snowfalls and rain over the past year have helped the acorns bloom larger and in greater numbers than they otherwise would have. No one in the state tracks the actual number of acorns every year, but observers from the Blue Hills to the Berkshires say they can’t remember a larger crop.

Wesley Autio, a professor who studies trees at the University of Massachusetts at Amherst,said he learned his lesson from the last time there was a bumper crop, when acorns destroyed his windshield. He has been parking his car inside this fall, but has not been spared altogether. Recently he got hit on the head while painting his house.

“It hurt,’’ he said. “You stand outside and you can hear acorns hitting everything - cars, metal roofs, and it makes a tremendous sound. We get a good crop every few years, but I don’t recall one as heavy as this. We already have a significant coating on our lawn, and most of them still aren’t down.’’

In the Blue Hills, Don McCasland, program director for the Blue Hill Observatory & Science Center, attributes the larger crop of acorns to the increased moisture as well as the cooler summer and lack of ozone hanging over the area. As a result, most of the trees seem a lot healthier, including white pines, which he and others report are dropping their pine cones in similarly large proportions as acorns.

He and others noted that the extra acorns will probably reverberate across the food chain, enabling more squirrels, skunks, chipmunks, mice, deer, and bears to survive the winter. As a result, predators such as hawks, coyote, foxes, and others are also likely to flourish next year, when there is more prey.

The main victims, they said, are gardeners, who are likely to see an increased rodent population nibbling on their bulbs and more tree seedlings sprouting in unwanted places.

“From what I see, it’s certainly a bumper crop, and that’s good and bad,’’ said John O’Keefe, retired coordinator of the Fisher Museum at Harvard Forest in Petersham, who said he has been hit one too many times by falling acorns. “It’s good for the wildlife, but it’s enough to make you want to wear a hard hat.’’

For Bob Hebeler, owner of the Acorn Alpaca Ranch on Acorn Street in Millis, the danger is that the alpaca he raises will eat too many acorns, which he said can be toxic to the animals in large quantities. So when a tree limb falls or too many acorns pile up in their grazing area, he does his best to clear them.

The other danger is that it scares them or anyone else who approaches the steel barn on his property, which is surrounded by hundreds of oaks. “Whenever you’re in there now, it sounds like gunshots going off,’’ he said. “They just ping off the roof, almost like squirrels are throwing them at you.’’

Along the Muddy River this week, the falling nuts from the flora canopy had Pnina Axelrod hoofing it for open sky while she held a book of poems over her head.

“It’s like it’s raining acorns,’’ said Axelrod, 79, of Newton.

Marvin Wang, 41, of Jamaica Plain, steered his bicycle around the clumps of crushed shells scattered on the path. “You have to keep enough momentum not to slip on them,’’ he said.

Then there was Robert Lofgren Jr., who sat on a bench under a patch of clear sky, waiting for the wind to die down before he ventured to his doctor’s office. The 49-year-old from Reading was wearing a knee brace and uses a cane to walk.

The ground in front of him looked treacherous.

“I don’t want to get bombarded, and I wish someone would clear the path,’’ he said. “If I fall, that’s it for my knee.’’